1. Field of the Invention
The invention is in the field of energy storage devices.
2. Description of the Related Art
Electric double layer capacitors (EDLCs), sometimes referred to as supercapacitors or ultracapacitors, are increasingly being used in power applications because of their high power performance, long cycle life, exceptional cycle efficiency, stable operation over a wide range of temperatures, and unexcelled reliability. Such EDLCs offer significant benefits over aluminum electrolytic capacitors, which are notoriously unreliable. However, there is a continuing need for improvements in performance and other specifications of capacitor devices.